[R] How to search for a sequence(and its combination) inside a vector?
Berend Hasselman
bhh at xs4all.nl
Sat Jul 20 18:24:29 CEST 2013
On 20-07-2013, at 18:05, C W <tmrsg11 at gmail.com> wrote:
> Hi R list,
>
> I have a sequence repeating 1:15 . Some numbers are deleted. I want
> to find how many times 1, 2, 3 appeared.
> Basically, I want to "grab" the beginning of the sequence and tally it up.
>
> R code:
>
>> vec <- c(1, 2, 3, 4, 5, 6, 7, 8, 13, 1, 2, 3, 5, 7, 8, 10, 12, 13, 14,
> 15, 1, 2, 3, 5, 6, 10, 12, 13, 1, 2, 3, 4, 5, 6, 7, 12, 13, 14,
> 15, 1, 2, 3, 6, 9, 10, 11, 13, 14, 1, 7, 10, 13, 1, 2, 3, 4,
> 6, 7, 9, 11, 14, 1, 2, 3, 5, 9, 10, 11, 12, 14, 1, 2, 3, 4, 1,
> 2, 3, 4, 11, 12, 14, 1, 2, 3, 4, 8, 11, 12, 1, 2, 3, 4, 5, 7,
> 8, 9, 11, 12, 15, 3, 14, 1, 2, 3, 6, 10, 11, 13, 14, 1)
>
>> a <- vec %in% c(1, 2, 3)
>> a
> [1] TRUE TRUE TRUE FALSE FALSE FALSE FALSE FALSE FALSE TRUE
> TRUE TRUE FALSE FALSE
> [15] FALSE FALSE FALSE FALSE FALSE FALSE TRUE TRUE TRUE FALSE
> FALSE FALSE FALSE FALSE
> [29] TRUE TRUE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
> FALSE TRUE TRUE TRUE
> [43] FALSE FALSE FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE
> TRUE TRUE TRUE FALSE
> [57] FALSE FALSE FALSE FALSE FALSE TRUE TRUE TRUE FALSE FALSE
> FALSE FALSE FALSE FALSE
> [71] TRUE TRUE TRUE FALSE TRUE TRUE TRUE FALSE FALSE FALSE
> FALSE TRUE TRUE TRUE
> [85] FALSE FALSE FALSE FALSE TRUE TRUE TRUE FALSE FALSE FALSE
> FALSE FALSE FALSE FALSE
> [99] FALSE TRUE FALSE TRUE TRUE TRUE FALSE FALSE FALSE FALSE FALSE TRUE
>
>> rle(a)
> Run Length Encoding
> lengths: int [1:29] 3 6 3 8 3 5 3 8 3 6 ...
> values : logi [1:29] TRUE FALSE TRUE FALSE TRUE FALSE ...
>
> What should I do after this?
>
Well how about
sum(a)
or
b <- rle(a)
sum(b$lengths[b$values])
Berend
> Thanks,
> Mike
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
More information about the R-help
mailing list